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Brief note: There is No Software (Friedrich Kittler): 20:49 (2006.10.04:3 research#94 xxxxx_at_piksel_notes#45)

[quote]

This all-important property of being programmable has, in all evidence, nothing to do with software; it is an exclusive feature of hardware, more or less suited as it is to house some notation system. When Claude Shannon, in 1937, proved in what is probably the most consequential MA thesis ever written that simple telegraph switching relays can implement by means of their different interconnections the whole of Boolean algebra, such a physical notation system was established.

When meanings come down to sentences, sentences to words, and words to letters, there is no software at all. Rather, there would be no software if computer systems were not surrounded any longer by an environment of everyday languages.

notes today (in conversation with Eva Verhoeven): 19:55 (2006.10.04:2 research#93 xxxxx_at_piksel_notes#44)

1] flip-flop time machine

(first ref in search offers:

http://www-personal.umich.edu/~reginald/timemchn.html

)

2] Alice in Wonderland CPU mechanisms - instruction set also with reference to symmetry which could be across CPU components/multiple CPUs - Alice is itself the communication mechanism (off with her head as propogated instruction). symmetry of the NAND gates in the S/R flipflop - also ahead of itself in time-machine reference above.

time-machine/Alice CPU of chained cells and gates. instruction futures

SIMPLE communicates with the outside world via thirty-three pins. 13:42 (2006.10.04:1 research#92 lispcpu#3 tech_notes#287 xxxxx_at_piksel_notes#43)

[further notes on Steele and Sussman's LispCPU]

1] Microcode:

quote [p35]:

Each of the two parts, EVAL and GC, is itself divided into two parts: registers and controller. The registers provide storage for type/pointer words, and are connected by a common bus in each part. Each controller is a finite-state machine implemented as a PLA, plus some random logic. Each PLA is organised as a micro-code ROM, addressed by a "Micro-PC" and yielding a set of control signals, including register controls and a new micro_PC indicating the next state.

signals enumerated on p36

p39. [SIMPLE Microcode] There are five kinds of operation EVAL can request from the GC (which give EVAL the step-eval signal to advance):

NOP, CAR/CDR, CONS/NCONS, RPLACD and load/store Q (one of GC's registers).

p40:

[quote]

The CONS operation accepts a car pointer from the E bus, takes the contents of Q to be the cdr pointer and then allocates a new two-word cell containing the car and cdr. A pointer to the result, with type 0 (list) is left in Q.

The Microcoded PLA is produced by software from the assembly listing (p48+) produced by the micro-assembler software from the listing (p43+)

2] The register cell

[p63]

One-bit register cell. The signal LD during O/1 loads the cell from the data bus. The signal RD during O/1 drives the bus from the cell. The cell is refreshed during O/2.